Methods for purifying 5-(halomethyl)furfural

ABSTRACT

The present disclosure provides methods for purifying a 5-(halomethyl)furfural composition, including 5-(chloromethyl)furfural, at operating conditions that decrease or minimize the decomposition or degradation of 5-(chloromethyl)furfural during the process. The methods may employ certain solvents, operating conditions, and/or techniques (e.g., gas stripping). The gaseous 5-(halomethyl)furfural produced from the process can be condensed or deposited to yield 5-(halomethyl)furfural in liquid or solid form. The solid 5-(halomethyl)furfural may be amorphous or crystalline.

CROSS-REFERENCE TO RELATED APPLICATION

This is application is a continuation application of InternationalApplication PCT/US2014/024949, with an international filing date of Mar.12, 2014, which claims priority to and the benefit of U.S. ProvisionalPatent Application No. 61/785,760, filed Mar. 14, 2013, the disclosuresof which are incorporated herein by reference in their entireties.

FIELD

The present disclosure relates generally to the production of furfuralcompounds, and more specifically to the purification of5-(halomethyl)furfural, such as 5-(chloromethyl)furfural.

BACKGROUND

Efforts to reduce dependence on fossil fuels for transportation fuel andas feedstock for industrial chemicals have been undertaken for decades,with a particular focus on enabling economic feasibility of renewablefeedstocks. Heightened efforts are being made to more effectivelyutilize renewable resources and develop “green” technologies, due tocontinued long-term increases in the price of fuel, increasedenvironmental concerns, continued issues of geopolitical stability, andrenewed concerns for the ultimate depletion of fossil fuels.

Cellulose in biomass is commonly used as a feedstock for biofuelproduction. For example, cellulose can be used to produce ethanol.Cellulose can also be used to produce furan-based biofuels by way of5-(halomethyl)furfural, such as 5-(chloromethyl)furfural (CMF). CMF canbe converted into 5-(ethoxymethyl)furfural, a compound considered as apromising diesel fuel additive. Alternatively, CMF can also be convertedinto 5-methylfurfural, another compound considered as a promising abiofuel candidate.

The production of CMF from cellulose was first described in the early1900s. Currently, various synthetic routes are known in the art toproduce CMF. CMF is typically produced as an oily residue that can bepurified by distillation. See e.g., Szmant & Chundury, J. Chem. Tech.Biotechnol. 1981, 31, 205-212. CMF, however, is known to decompose athigh temperatures. This presents a challenge for purifying CMF bydistillation or for obtaining gaseous CMF.

Thus, what is desirable are new methods for purifying a5-(halomethyl)furfural composition or obtaining gaseous5-(halomethyl)furfural at commercially viable operating conditions thatdecrease or minimize decomposition of the 5-(halomethyl)furfural.

BRIEF SUMMARY

The present disclosure addresses this need by providing methods forobtaining gaseous 5-(halomethyl)furfural or purifying a5-(halomethyl)furfural composition in a way that can decrease orminimize decomposition of the 5-(halomethyl)furfural. The5-(halomethyl)furfural may be 5-(chloromethyl)furfural or5-(bromomethyl)furfural.

In one aspect, provided is a method that includes boiling a mixturehaving 5-(halomethyl)furfural and solvent to produce gaseous5-(halomethyl)furfural. In some embodiments, the solvent may have aboiling point at or above the boiling point of the5-(halomethyl)furfural. In certain embodiments where the5-(halomethyl)furfural is 5-(chloromethyl)furfural, the solvent may havea boiling point of at least 240° C. at standard pressure (e.g., 1 atm).

In other aspect, provided is a method that includes contacting5-(halomethyl)furfural with a stripping agent to produce gaseous5-(halomethyl)furfural, wherein the stripping agent has a vapor pressureabove the vapor pressure of 5-(halomethyl)furfural. In some embodiments,provided is a method that includes contacting a mixture comprising5-(halomethyl)furfural and solvent with a stripping agent to producegaseous 5-(halomethyl)furfural, wherein the stripping agent has a vaporpressure above the vapor pressure of 5-(halomethyl)furfural.

In some embodiments of the methods above, the solvent includes one ormore aromatic solvents, one or more heavy alkane solvents, one or moreester solvents, one or more silicone oils, or any combinations ormixtures thereof. In certain embodiments, the solvent includes one ormore alkyl phenyl solvents. In one embodiment, the solvent includessulfolane, hexadecane, heptadecane, octadecane, icosane, heneicosane,docosane, tricosane, tetracosane, naphthalene, anthracene,tetramethylnaphthalene, or any combinations or mixtures thereof.

In some embodiments that may be combined with any of the foregoingembodiments, the method further includes collecting the gaseous5-(halomethyl)furfural. In other embodiments that may be combined withany of the foregoing embodiments, the method further includes condensingthe gaseous 5-(halomethyl)furfural to obtain purified5-(halomethyl)furfural in liquid form. In yet other embodiments that maybe combined with any of the foregoing embodiments, the method furtherincludes depositing the gaseous 5-(halomethyl)furfural to obtainpurified 5-(halomethyl)furfural in solid form.

Provided herein is also a system that includes: a purificationapparatus; 5-(halomethyl)furfural; and solvent having a boiling point ator above the boiling point of the 5-(halomethyl)furfural. In someembodiments of the system, the solvent in the system may include one ormore aromatic solvents, one or more heavy alkane solvents, one or moreester solvents, one or more silicone oils, or any combinations ormixtures thereof. In certain embodiments, the solvent includes one ormore alkyl phenyl solvents. In one embodiment, the solvent includessulfolane, hexadecane, heptadecane, octadecane, icosane, heneicosane,docosane, tricosane, tetracosane, naphthalene, anthracene,tetramethylnaphthalene, or any combinations or mixtures thereof. Thepurification apparatus may be configured for continuous or batchprocessing.

DESCRIPTION OF THE FIGURES

The present application can be best understood by reference to thefollowing description taken in conjunction with the accompanyingfigures, in which like parts may be referred to by like numerals.

FIG. 1 depicts an exemplary apparatus suitable for continuous processingwith the methods provided herein.

FIG. 2 depicts an exemplary apparatus suitable for batch processing withthe methods provided herein.

FIG. 3 depicts another exemplary apparatus for the methods providedherein.

DETAILED DESCRIPTION

The following description sets forth exemplary methods, parameters andthe like. It should be recognized, however, that such description is notintended as a limitation on the scope of the present disclosure but isinstead provided as a description of exemplary embodiments.

In one aspect, provided is a method for obtaining gaseous5-(halomethyl)furfural or purifying a 5-(halomethyl)furfural compositionby boiling a mixture having 5-(halomethyl)furfural and particularsolvents. In some embodiments, the solvent may have a boiling point ator above the boiling point of the 5-(halomethyl)furfural. In certainembodiments where the 5-(halomethyl)furfural is5-(chloromethyl)furfural, the solvent may have a boiling point of atleast 240° C. at standard pressure (e.g., 1 atm). Examples of suitablesolvents may include, for example, alkyl phenyl solvents (e.g., linearalkyl benzenes), heavy alkane solvents, ester solvents, aromaticsolvents, silicone oils, or any combinations or mixtures thereof. The5-(halomethyl)furfural may be 5-(chloromethyl)furfural or5-(bromomethyl)furfural.

In another aspect, provided is a method for obtaining gaseous5-(halomethyl)furfural or purifying a 5-(halomethyl)furfural compositionby gas stripping. In some embodiments, such method includes contacting astripping agent with 5-(halomethyl)furfural to vaporize the5-(halomethyl)furfural. In other embodiments, such method includescontacting a stripping agent with a mixture having5-(halomethyl)furfural and the particular solvents described herein tovaporize the 5-(halomethyl)furfural in the 5-(halomethyl)furfuralcomposition. The stripping agent used in this method has a vaporpressure above the vapor pressure of 5-(halomethyl)furfural.

The methods provided herein may be employed to produce gaseous5-(halomethyl)furfural, or to purify a 5-(halomethyl)furfuralcomposition, at conditions that can decrease or minimize decompositionof the 5-(halomethyl)furfural. Further, the 5-(halomethyl)furfuralobtained by the methods described herein may be in liquid form or solidform, including crystalline forms. For example, in one variation,provided is a method for distilling 5-(halomethyl)furfural in thepresence of the solvents described herein at conditions that candecrease or minimize decomposition of the 5-(halomethyl)furfural. Itshould be understood that distilling 5-(halomethyl)furfural involvesboiling 5-(halomethyl)furfural to form gaseous 5-(halomethyl)furfural,and condensing or depositing the gaseous 5-(halomethyl)furfural in aliquid or solid form, respectively.

The gaseous 5-(halomethyl)furfural may be collected, condensed,deposited, or fed in its gaseous state into another reaction. The5-(halomethyl)furfural composition, the methods, and the purified5-(halomethyl)furfural obtained are each described in further detailbelow.

5-(Halomethyl)furfural Provided For Methods

The 5-(halomethyl)furfural provided for the methods described herein maybe pure, such that the methods are employed to obtain a gaseous form5-(halomethyl)furfural. The 5-(halomethyl)furfural provided for themethods described herein may also have one or more impurities, such thatthe methods are employed to separate the 5-(halomethyl)furfural from oneor more of the impurities.

Any suitable sources (including any commercially available sources) andmethods known in the art may be used to prepare 5-(halomethyl)furfuralfor use in the methods described herein. Methods known in the art toprepare 5-(halomethyl)furfural are described in, for example, U.S. Pat.No. 7,829,732; Fenton & Gostling, J. Chem. Soc., 1899, 75, 423; Haworth& Jones, J. Chem. Soc., 1944, 667; Szmant & Chundury, J. Chem. Tech.Biotechnol. 1981, 31, 205-212; and Mascal and Nikitin, ChemSusChem,2009, 2, 859-861; Brasholz et al., Green Chem., 2011, 13, 1114-1117.

Feedstock

Feedstocks suitable for producing 5-(halomethyl)furfural may include anymaterials that contain six-carbon (C6) sugars. The C6 sugars may bemonomeric, dimeric, or polymeric. It should be understood that“six-carbon sugars” or “C6 sugars” refer to sugars where the monomericunit has six carbons. Moreover, the C6 sugars have alcohol groups neededfor conversion into 5-(halomethyl)furfural.

In one embodiment, the C6 sugars can be cellulose or provided inhemicellulose. One of skill in the art would recognize that celluloseand hemicellulose can be found in biomass (e.g., cellulosic biomass orlignocellulosic biomass). Biomass can be any plant material made up oforganic compounds relatively high in oxygen, such as carbohydrates, andalso contain a wide variety of other organic compounds. The biomass mayalso contain other materials that are not converted to5-(halomethyl)furfural, such as inorganic salts and clays.

Biomass may be pretreated to help make the sugars in the biomass moreaccessible, by disrupting the crystalline structures of cellulose andhemicellulose and breaking down the lignin structure (if present).Common pretreatments known in the art involve, for example, mechanicaltreatment (e.g., shredding, pulverizing, grinding), concentrated acid,dilute acid, SO₂, alkali, hydrogen peroxide, wet-oxidation, steamexplosion, ammonia fiber explosion (AFEX), supercritical CO₂ explosion,liquid hot water, and organic solvent treatments.

Biomass may originate from various sources. For example, biomass mayoriginate from agricultural materials (e.g., corn stover, rice hulls,peanut hulls, spent grains), processing waste (e.g., paper sludge), andrecycled cellulosic materials (e.g., cardboard, old corrugatedcontainers (OCC), old newspaper (ONP), or mixed paper). Other examplesof suitable biomass may include wheat straw, paper mill effluent,newsprint, municipal solid wastes, wood chips, forest thinings, slash,miscanthus, switchgrass, sorghum, bagasse, manure, wastewater biosolids,green waste, and food/feed processing residues.

In other embodiments, the C6 sugars can be glucose, fructose (e.g., highfructose corn syrup), cellobiose, sucrose, lactose, and maltose. Anystereoisomers of such C6 sugars may also be used in the methodsdescribed herein.

In yet other embodiments, the feedstock may be a saccharide composition.For example, the sugar composition may include a single saccharide or amixture of saccharides such as fructose, glucose, sucrose, lactose andmaltose.

Impurities

Methods known in the art to prepare 5-(halomethyl)furfural typicallyyield one or more impurities in the product mixture. These impuritiesmay be bi-products and/or residual starting materials, or anydecomposition or degradation products thereof, from the reaction(s) usedto prepare 5-(halomethyl)furfural.

For example, 5-(chloromethyl)furfural prepared from cellulosic materialsaccording to the methods described in U.S. Pat. No. 7,829,732 can yieldbi-products such as 2-(2-hydroxyacetyl)furan, 5-(hydroxymethyl)furfural,levulinic acid, and humic materials. Examples of other bi-products anddecomposition or degradation products may include furfural and formicacid. Examples of residual starting materials may include residualsugars (e.g., C5 monomeric sugars, C6 monomeric sugars, C5 oligomericsugars, C6 oligomeric sugars), residual biomass (e.g., corn stover, oldcorrugated containers, old newspaper). Examples of residual reagents mayinclude residual acid (e.g., hydrochloric acid). One or more thebi-products, residual starting materials, and residual reagents, and anydecomposition or degradation products thereof, may be part of the5-(halomethyl)furfural composition that is provided for the methodsdescribed herein.

Thus, in some embodiments, the one or more impurities present in the5-(halomethyl)furfural composition provided for the methods hereininclude 2-(2-hydroxyacetyl)furan, 5-(hydroxymethyl)furfural, levulinicacid, humic materials, furfural, formic acid, residual sugars (e.g., C5monomeric sugars, C6 monomeric sugars, C5 oligomeric sugars, C6oligomeric sugars), residual biomass (e.g., corn stover, old corrugatedcontainers, old newspaper), and/or residual acid (e.g., hydrochloricacid).

In certain embodiments, the 5-(halomethyl)furfural composition used inthe methods herein has less than 5 wt %, less than 4 wt %, less than 3wt %, less than 2 wt %, less than 1 wt %, less than 0.5 wt %, less than0.4 wt %, less than 0.3 wt %, less than 0.2 wt %, less than 0.1 wt %,less than 0.01 wt %, less than 0.05 wt %, less than 0.001 wt % of acid(e.g., hydrochloric acid). The acid present in the5-(halomethyl)furfural composition may be residual from the reactionused to prepare the 5-(halomethyl)furfural, or may be the result ofdecomposition or degradation of 5-(halomethyl)furfural. It should beunderstood that the 5-(halomethyl)furfural composition used in themethods described herein may be washed (e.g., with a brine solution) todecrease the amount of acid present in the composition.

The 5-(halomethyl)furfural composition used in the methods herein may bein liquid or solid form, or a combination thereof. In one embodiment,the 5-(halomethyl)furfural composition is in liquid form. In anotherembodiment, the 5-(halomethyl)furfural composition is in solid form.

Boiling

Gaseous 5-(halomethyl)furfural may be obtained, or a5-(halomethyl)furfural composition may be purified, using certainsolvents at operating conditions that can decrease or minimizedecomposition or degradation of the 5-(halomethyl)furfural.

The 5-(halomethyl)furfural and the solvent may be provided to theapparatus separately or together. For example, when the5-(halomethyl)furfural and the solvent are both in liquid form, they maybe provided to the apparatus as individual feed streams or as a combinedfeed stream.

Further, in some embodiments, the 5-(halomethyl)furfural, the solvent,or both may be heated to the operating temperature or close to theoperating temperature before they are provided (either separately ortogether) to the apparatus. The heat source may serve to primarilymaintain the operating temperature of the apparatus. In otherembodiments, the 5-(halomethyl)furfural, the solvent, or both may beprovided to the apparatus (either separately or combined) at or belowthe operating temperature, and then heated to the operating temperatureusing the heat source. In yet other embodiments, the5-(halomethyl)furfural, the solvent, or both may be heated above theoperating temperature before they are provided (either separately ortogether) for flash distillation, where the pre-heated5-(halomethyl)furfural and/or the solvent may be subjected to anoperating pressure below the vapor pressure of the5-(halomethyl)furfural to cause boiling.

Solvents

The solvents used may be obtained from any source, including anycommercially available source. In some embodiments, the solvents usedherein have a boiling point at or above the boiling point of the5-(halomethyl)furfural. In some embodiments, the solvent has a boilingabove the boiling point of the 5-(halomethyl)furfural. The boilingpoints may be determined at any pressure, for example, at the operatingpressure.

The boiling point of a substance is the temperature at which the vaporpressure of the substance equals the pressure surrounding the liquid(e.g., in the apparatus), and the liquid changes into a vapor. Boilingis vaporization of a liquid when the liquid is heated to or above itsboiling point, and/or when the pressure of the liquid is reduced to orbelow its vapor pressure. Further, one of skill would recognize that theboiling point of a liquid varies depending on the surroundingenvironmental pressure (e.g., in the apparatus). For example, a liquidin a vacuum has a lower boiling point than when that liquid is atatmospheric pressure. The boiling points of a substance (such as5-(halomethyl)furfural) at a given pressure may be determined by anysuitable methods known in the art.

It is intended and understood that the boiling point of the solvent andthe boiling point of the 5-(halomethyl)furfural used in selecting thesolvent are measured in the absence of the 5-(halomethyl)furfuralcomposition. By way of an example, the selection of the solvent may bebased on the boiling point of the solvent before the solvent has beenfed into the apparatus and combined with the 5-(halomethyl)furfuralcomposition.

In certain embodiments, the boiling point of the solvent is at least 20°C., at least 30° C., at least 40° C., at least 50° C., at least 60° C.,at least 70° C., at least 80° C., at least 90° C., at least 100° C., atleast 150° C., at least 200° C., at least 250° C. or at least 300° C.above the boiling point of the 5-(halomethyl)furfural at the operatingpressure for the distillation. In particular embodiments, the boilingpoint of the solvent is between 20° C. and 500° C., between 20° C. and300° C. , between 20° C. and 200° C., between 20° C. and 100° C.,between 50° C. and 300° C., or between 100° C. and 300° C. above theboiling point of the 5-(halomethyl)furfural at the operating pressure.

In certain embodiments where the 5-(halomethyl)furfural is5-(chloromethyl)furfural, the solvent may have a boiling point of atleast 240° C., at least 245° C., at least 250° C., or at least 255° C.at standard pressure (e.g., 1 atm).

In some embodiments, the solvents suitable for use in the methodsprovided herein at least partially dissolve 5-(halomethyl)furfural.

In other embodiments, the solvents suitable for use in the methodsprovided herein may include, for example, aromatic solvents (includingalkyl phenyl solvents), alkyl solvents, halogenated solvents, siliconeoils, or any combinations or mixtures thereof, that have a boiling pointor a boiling point range above the boiling point of5-(halomethyl)furfural. It should be understood that a solvent may fallwithin one or more classes described above. For example, Wibaryl® A isan aromatic solvent, that can more specifically be classified as analkyl phenyl solvent.

In certain embodiments, the solvent may include one or more alkyl phenylsolvents, such as one or more linear alkyl benzenes. As used herein, “analkyl phenyl solvent” refers to a class of solvents that have one ormore alkyl chains attached to one or more phenyl or phenyl-containingring systems. The alkyl phenyl solvent may be referred to as analkylbenzene or a phenylalkane. One skilled in the art would recognizethat certain phenylalkanes may also be interchangeably referred to as analkylbenzene. For example, (1-phenyl)dodecane and dodecylbenzene referto the same solvent.

In certain embodiments, the solvent includes one or more alkylbenzenes.Examples may include (monoalkyl)benzenes, (dialkyl)benzenes, and(polyalkyl)benzenes. In certain embodiments, the alkylbenzene has onealkyl chain attached to one benzene ring. The alkyl chain may have oneor two points of attachment to the benzene ring. Examples ofalkylbenzenes with one alkyl chain having one point of attachment to thebenzene ring include dodecylbenzene. In embodiments where the alkylchain has two points of attachment to the benzene ring, the alkyl chainmay form a fused cycloalkyl ring to the benzene. Examples ofalkylbenzenes with one alkyl having two points of attachment to thebenzene ring include tetralin. It should be understood that the fusedcycloalkyl ring may be further substituted with one or more alkylchains.

In other embodiments, the alkylbenzene has two or more alkyl chains(e.g., 2, 3, 4, 5, or 6 alkyl chains) attached to one benzene ring.

In yet other embodiments, the alkylbenzene is an alkyl-substituted fusedbenzene ring system. The fused benzene ring system may include benzenefused with one or more heterocyclic rings. In one embodiment, the fusedbenzene ring system may be two or more fused benzene rings, such asnaphthalene. The fused benzene ring system may be optionally substitutedby one or more alkyl chains. For example, such alkyl-substituted fusedbenzene ring system may include tetramethylnaphthalene.

In some embodiments, the solvent includes phenylalkane. Examples mayinclude (monophenyl)alkanes, (diphenyl)alkanes, and (polyphenyl)alkanes.In certain embodiments, the phenylalkane has one phenyl ring attached toone alkyl chain. In one embodiment, the alkyl chain attached to thephenyl ring may be an alkyl chain with at least eight carbons (e.g., C₈₊alkyls), such as a C₈₋₂₀ alkyl or a C₁₃₋₂₀ alkyl. The phenyl ring may beattached to any carbon along the alkyl chain. For example, the phenylalkyl having one alkyl chain may be (1-phenyl)dodecane or(2-phenyl)dodecane.

In other embodiments, the phenylalkane has two or more phenyl ringsattached to one alkyl chain.

The alkyl phenyl solvents may be linear or branched, based on the alkylchain(s) attached to the phenyl or phenyl-containing ring systems.“Alkyl” refers to a monoradical saturated hydrocarbon chain. The lengthof the alkyl chain may vary. In certain embodiments, the alkyl chain maybe 1 to 20 carbon atoms (e.g., C₁₋₂₀ alkyl). In one embodiment, thealkyl chain may be 4 to 15 carbons (e.g., C₄₋₁₅ alkyl), 8 to 20 carbons(e.g., C₈₋₂₀ alkyl), or 10 to 13 carbons (e.g., C₁₀₋₁₃ alkyl).

The alkyl chain may be linear or branched. Linear alkyl chains mayinclude, for example, n-propyl, n-butyl, n-hexyl, n-heptyl, n-octyl,n-nonanyl, n-decyl, n-undecyl, and n-dodecyl. Branched alkyl chains mayinclude, for example, isopropyl, sec-butyl, isobutyl, tert-butyl, andneopentyl. In some embodiments where the solvent includes two or morealkyl chains, certain alkyl chains may be linear, whereas other alkylchains may be branched. In other embodiments where the solvent includestwo or more alkyl chains, all the alkyl chains may be linear or all thealkyl chains may be branched.

For example, the solvent may include one or more linear alkylbenzenes(“LAB s”). Linear alkylbenzenes are a class of solvents having theformula C₆H₅C_(n)H_(2n+1). For example, in one embodiment, the linearalkylbenzene is dodecylbenzene. Dodecylbenzene is commerciallyavailable, and may be “hard type” or “soft type”. Hard typedodecylbenzene is a mixture of branched chain isomers. Soft typedodecylbenzene is a mixture of linear chain isomers. In one embodiment,the solvent includes hard type dodecylbenzene.

In some embodiments, the solvent may include any of the alkyl phenylsolvents described above, in which the phenyl ring is substituted withone or more halogen atoms. In certain embodiments, the solvent includesan alkyl(halobenzene). For example, the alkyl(halobenzene) may includealkyl(chlorobenzene). In one embodiment, the halo substituent for thephenyl ring may be, for example, chloro, bromo, or any combinationthereof.

In some embodiments, the solvent may include one or more heavy alkanes.“Heavy alkanes” include saturated hydrocarbon chains containing at least8 carbon atoms (e.g., C₈₊ alkane), at least 10 carbon atoms (e.g.,C₁₀₊alkane), or at least 13 carbon atoms (e.g., C₁₃₊ alkane). In someembodiments, the heavy alkane may have 8 to 100 carbon atoms (e.g.,C₈₋₁₀₀ alkanes), 8 to 50 carbon atoms (e.g., C₈₋₅₀ alkanes), 8 to 25carbon atoms (e.g., C₈₋₂₅ alkanes), or 10 to 20 carbon atoms (e.g.,C₁₀₋₂₀ alkanes). In other embodiments, the solvent may include one ormore heavy alkanes, wherein at least one heavy alkane has at least 13carbon atoms. In one embodiment, the solvent may include hexadecane,heptadecane, octadecane, icosane, heneicosane, docosane, tricosane,tetracosane, or any combinations or mixtures thereof.

In other embodiments, the solvent may include one or more esters. Insome embodiments, the esters may be fatty acids. In certain embodiments,the esters may be (heavy alkyl)-esters, e.g., C₈₊alkyl-(O)OH. In someembodiments, the (heavy alkyl)-esters may have 8 to 100 carbon atoms(e.g., C₈₋₁₀₀ alkyl-(O)OH), 8 to 50 carbon atoms (e.g., C₈₋₅₀alkyl-(O)OH), 8 to 25 carbon atoms (e.g., C₈₋₂₅ alkyl-(O)OH), or 10 to20 carbon atoms (e.g., C₁₀₋₂₀ alkyl-(O)OH). In one embodiment, thesolvent may include hexadecanoic acid.

In other embodiments, the solvent may include one or more aromaticsolvents. In some embodiments, the aromatic solvent is a C₆₋₂₀ aromaticsolvent, or a C₆₋₁₅ aromatic solvent. In one embodiment, the solventincludes naphthalene, naphthenic oil, alkylated naphthalene, diphenyl,polychlorinated biphenyls, polycyclic aromatic hydrocarbons, or anycombinations or mixtures thereof.

In yet other embodiments, the solvent may include one or more siliconeoils. In certain embodiments, the solvent includes one or more alkylsiloxanes.

The solvent may be a single solvent or may include a mixture ofsolvents. If the solvent is a mixture of solvents, the solvent mixturehas a boiling point at or above the boiling point of the5-(halomethyl)furfural at the operating pressure. For example, in someembodiments, the solvent may be a mixture of (i) one or more alkylphenyl solvents, and (ii) one or more aromatic solvents. For example, inanother embodiment, the solvent may be a mixture of toluene and one ormore other solvents such as camphor, anthracene, and anthraquinone. Itshould be understood that if the solvent mixture has a range of boilingpoints, such range may encompass the boiling point of the5-(halomethyl)furfural at the operating pressure but the entire rangeneed not be above the boiling point of the 5-(halomethyl)furfural at theoperating pressure.

It should also be understood that the solvent may include any substancethat is a liquid at the operating temperature and pressure, but suchsubstance may not be a liquid at standard temperature and pressure.

Exemplary solvents that may be used in the methods and compositionsdescribed herein include alkyl benzenes, sulfolane, heavy alkanes,diphenyl ethers and polyphenyl ethers, and other aromatic solvents. Incertain embodiments, the solvent includes alkyl benzenes. In oneembodiment, the solvent includes dodecylbenzene. An example of suchdodecylbenzene is Marlican®. In other embodiments, the alkyl benzene mayhave alkyl side chains having at least 10 carbon atoms, at least 13carbon atoms, or 10 to 40 carbon atoms, or 10 to 20 carbon atoms, or 10to 13 carbon atoms, or 13 to 30 carbon atoms. Suitable alkyl benzenesmay include, for example, Wibaryl® (e.g., benzene substituted withC₁₀₋₁₃ alkyl chain), Wibaryl® F. (heavy alkylate), Wibaryl® A(diphenylalkanes, wherein the alkyl chains are C₁₀₋₁₃ alkyl chains),Wibaryl® B (dialkylbenzenes, wherein the alkyl chains are C₁₀₋₁₃ alkylchains), Wibaryl® AB (a mixture of diphenylalkanes and dialkylbenzenes),Wibaryl® R (oligo- and polyalkylbenzenes), Cepsa Petrelab® 500-Q (linearalkylbenzene containing side alkyl chains of 10-13 carbon atoms), CepsaPetrelab® 550-Q (linear alkylbenzene containing side alkyl chains of10-13 carbon atoms), Cepsa Petrene® 900-Q (heavy alkylbenzene containingprimarily dialkylbenzenes), Synnaph® AB 3 (heavy alkyl benzene),Synnaph® DAB4 (dialkylbenzene), and Therminol® 55 (benzene substitutedwith C₁₃₋₃₀ alkyl chains).

In other embodiments, the solvent includes phenyl ethers, includingmonophenyl ethers, diphenyl ethers and polyphenyl ethers. Suitablephenyl ethers include, for example, Santovac® 5 and Santovac® 7. In yetother embodiments, the solvent includes other aromatic solvents. Thearomatic solvent may include at least one alkyl chain substituent, andsuch aromatic solvents may include monocyclic aromatic ring system orbicyclic or polyciclic aromatic systems (including fused ring systems).Examples of such aromatic solvents include, for example, naphthalene,anthracene, Dowtherm® (mixture of biphenyl and diphenyl oxide),Dowtherm® G (di- and tri-aryl ethers), Dowtherm® Q (a mixture ofdiphenylethane and alkylated aromatics), and Dowtherm® MX (a mixture ofalkylated aromatics). As discussed above, any combinations or mixturesof such solvents may also be used.

Operating Conditions

When the solvents described above are used, the methods to obtaingaseous 5-(halomethyl)furfural or to purify 5-(halomethyl)furfural maybe performed at pressures that are higher than what are currently usedin the art.

The operating pressure refers to the pressure in the apparatus at theinterface between the bottoms liquid and the gas phase. In someembodiments, the operating pressure is at least 30 ton, at least 50torr, at least 100 torr, at least 125 torr, at least 150 torr, at least200 torr, or at least 250 torr. In certain embodiments, the operatingpressure is between 50 torr and 2000 torr, between 50 torr and 1250torr, between 100 torr and 1400 torr, between 100 torr and 1000 torr,between 100 torr and 800 torr, between 100 torr and 400 torr, between125 torr and 350 torr, between 150 torr and 250 torr, between 50 and 500torr, or between 50 torr and 300 torr.

The operating temperature refers to the temperature in the apparatus atthe interface between the bottoms liquid and the gas phase. As discussedin further detail below, the apparatus may be configured with anexternal heat source, an internal heat source, or a combination thereof.For example, the apparatus may be configured with an external heatsource, such as a heat exchanger. The apparatus may also be configuredwith an internal heat source, such as a heat coil.

In some embodiments, the operating temperature is at least 60° C., atleast 70° C., at least 80° C., at least 100° C., at least 150° , orleast 200° C. In certain embodiments, the operating temperature isbetween 60° C. and 400° C., between 80° C. and 350° C., between 80° C.and 300° C., between 80° C. and 200° C., between 100° C. and 180° C., orbetween 120° C. and 160° C.

While pressure has been described in ton and temperature as degreesCelsius, one of skill in the art would be able to convert the pressureand temperature units to other commonly known units. For example,temperature may be expressed as Kelvin. Pressure may also be expressedas bar, atmosphere (atm), pascal (Pa) or pound-force per square inch(psi).

Gas Stripping

Gaseous 5-(halomethyl)furfural may be obtained, or5-(halomethyl)furfural may be purified, by gas stripping using astripping agent at operating conditions that can decrease or minimizedecomposition or degradation of the 5-(halomethyl)furfural. In someembodiments, gas stripping may be performed in the absence of thesolvents described herein. In other embodiments, gas stripping isperformed with the solvents described herein.

Stripping Agent

A stripping agent may be fed to the apparatus and contacted with the5-(halomethyl)furfural composition to vaporize the5-(halomethyl)furfural. The stripping agent can be any substance thathas a vapor pressure at or above the vapor pressure of5-(halomethyl)furfural, and may be obtained from any source, includingany commercially available source.

The stripping agent may be provided to the apparatus as a gas or aliquid. In one embodiment, the stripping agent is a gas. In someembodiments, the gas may be provided to the apparatus separately fromthe 5-(halomethyl)furfural composition. For example, the gas may be aninert gas (e.g., nitrogen, argon, helium, or any combinations ormixtures thereof).

In other embodiments, the stripping agent may be a gas that is dissolvedor partially dissolved in the 5-(halomethyl)furfural compositionprovided to the apparatus.

In yet other embodiments, the stripping agent may include any substancethat is a gas at the operating temperature and pressure, but suchsubstance may not be a gas at standard temperature and pressure. Forexample, the stripping agent may be a liquid that has a vapor pressureat or above the vapor pressure of 5-(halomethyl)furfural at theoperating conditions. In one embodiment, the stripping agent may betoluene, which is gaseous at operating conditions (e.g., 100° C. and 100torr), but is a liquid at standard temperature and pressure.

The stripping agent may be a single substance or may include a mixtureof substances. If the stripping agent is a mixture of substances, themixture at the operating conditions has a vapor pressure above the vaporpressure of the 5-(halomethyl)furfural. It should be understood that ifthe solvent mixture has a range of vapor pressures, such range mayencompass the vapor pressure of the 5-(halomethyl)furfural at theoperating pressure but the entire range need not be above the vaporpressure of the 5-(halomethyl)furfural at the operating pressure.

It should be understood that in certain exemplary embodiments, the5-(halomethyl)furfural composition and the particular solvents describedherein may be combined and contacted with the stripping agent to obtaingaseous 5-(halomethyl)furfural or to purify 5-(halomethyl)furfural.

Solvents

Any of the solvents described above may be used for the gas strippingmethod. For example, the solvents suitable for use in the gas strippingmethod may include alkyl phenyl solvents, aromatic solvents, alkylsolvents, halogenated solvents, silicone oils, or any combinations ormixtures thereof, that have a boiling point or a boiling point rangeabove the boiling point of 5-(halomethyl)furfural. In certainembodiments, the solvent may include one or more alkyl phenyl solvents,such as one or more linear alkyl benzenes.

Operating Conditions

When gas stripping as described above is employed, the method may beperformed at operating conditions that may decrease or minimizedecomposition of the 5-(halomethyl)furfural.

In some embodiments, the operating temperature is at least 60° C., atleast 70° C., at least 80° C., at least 100° C., at least 150° , orleast 200° C. In certain embodiments, the operating temperature isbetween 80° C. and 400° C., between 80° C. and 300° C., between 80° C.and 250° C., between 80° C. and 240° C., between 80° C. and 200° C.,100° C. and 180° C., or between 120° C. and 160° C.

In some embodiments, the operating pressure is at least 30 torr, atleast 50 torr, at least 100 torr, at least 125 torr, at least 150 torr,at least 200 torr, or at least 250 torr. In certain embodiments, theoperating pressure is between 50 torr and 10,000 torr, between 50 torrand 9000 torr, between 50 torr and 8000 torr, between 50 torr and 7000torr, between 50 torr and 6000 torr, between 50 torr and 5000 torr,between 50 torr and 4000 torr, between 50 torr and 3000 torr, between100 torr and 10,000 torr, between 100 torr and 4000 torr, between 100torr and 3000 torr, between 100 torr and 2000 torr, between 100 torr and400 torr, between 125 torr and 350 torr, or between 150 torr and 250torr.

5-(Haloinethyl)furfural Obtained from Methods

In some aspects, the methods described herein produce gaseous5-(halomethyl)furfural. The gaseous 5-(halomethyl)furfural may becollected, condensed, deposited, or fed in a gaseous state into anotherreaction.

In some embodiments, the gaseous 5-(halomethyl)furfural may be collectedin any suitable vessel, where the gaseous 5-(halomethyl)furfural may bestored for further use at a later time.

In other embodiments, the gaseous 5-(halomethyl)furfural may becondensed to obtain 5-(halomethyl)furfural in liquid form. Any suitablemethods or systems known in the art to condense a gas to a liquid may beused, including for example, a condenser.

In yet other embodiments, the gaseous 5-(halomethyl)furfural may bedeposited to obtain 5-(halomethyl)furfural in solid form. Any suitablemethods or systems known in the art to deposit a gas to obtain a solidmay be used. Where solid 5-(halomethyl)furfural is produced, the solidnature of the product may make it easier to handle than product inliquid form (including, for example, oil). For example, the solid5-(halomethyl)furfural can more easily and conveniently be stored andtransported. The solid 5-(halomethyl)furfural obtained may be amorphousor crystalline.

In yet other embodiments, the gaseous 5-(halomethyl)furfural may becollected in a reflux system and fed back into the system to maintainequilibrium in the apparatus. For example, a reflux system may be usedwhen the apparatus is a distillation column that includes trays orpacking materials.

Purity

The 5-(halomethyl)furfural obtained may have an increased overallpurity. One of skill in the art would recognize the various methods andtechniques to measure the purity of a sample. For example, components inthe sample can be identified and the amounts of such components can bemeasured by high-performance liquid chromatography (also known in theart as high-pressure liquid chromatography or HPLC), gaschromatography-mass spectrometry (GS-MS), magnetic resonancespectroscopy (e.g., ¹H-NMR, ¹³C-NMR), differential scanning calorimetry(DSC), or any combinations of such methods.

In some embodiments, the 5-(halomethyl)furfural obtained from themethods provided herein may have a purity of at least 90%, at least 95%,at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5%,or at least 99.9%. In one embodiment, the 5-(halomethyl)furfuralobtained from the methods provided herein has a purity between 95% and100%, between 95% and 99%, between 98% and 100%, or about 95%, about96%, about 97%, about 98%, about 99%, or about 100%.

Distillation/Stripping Yield

The methods provided herein may produce 5-(halomethyl)furfural with adistillation yield or stripping yield (as the case may be depending onthe method employed) of at least 10 wt %, 15 wt %, 20 wt %, 25 wt %, 30wt %, 35 wt %, 40 wt %, 45 wt %, 50 wt %, 55 wt %, 60 wt %, 65 wt %, 70wt %, 75 wt %, 80 wt %, 85 wt %, 90 wt %, 95 wt %, or 99 wt %, orbetween 10 wt % and 99 wt %, between 50 wt % and 99 wt %, between 60 wt% and 99 wt %, or between 70 wt % and 90 wt %. Distillation yield or thestripping yield is the ratio of the amount of 5-(halomethyl)furfuralcollected to the amount of 5-(halomethyl)furfural provided to theapparatus. In certain instances where 5-(halomethyl)furfural iscollected in a receiving flask, the distillation yield is the ratio ofthe amount of 5-(halomethyl)furfural collected in the receiving flask atthe end of the process to the amount of 5-(halomethyl)furfural providedto the still flask at the beginning of the process. In other instanceswhere a continuous process is employed, the distillation yield may bethe ratio of the amount of condensed or deposited 5-(halomethyl)furfuralto the amount of 5-(halomethyl)furfural fed to the apparatus.

It should be understood that reference to “about” a value or parameterherein includes (and describes) embodiments that are directed to thatvalue or parameter per se. For example, description referring to “aboutx” includes description of “x” per se. In other instances, the term“about” when used in association with other measurements, or used tomodify a value, a unit, a constant, or a range of values, refers tovariations of +/−5%.

It should also be understood that reference to “between” two values orparameters herein includes (and describes) embodiments that includethose two values or parameters per se. For example, descriptionreferring to “between x and y” includes description of “x” and “y” perse.

Downstream Products

The 5-(halomethyl)furfural produced according to the methods describedherein may be used in other chemical reactions, or further processedinto other furanic derivatives for biofuels, diesel additives, orplastics. For example, CMF may be converted into dimethylfuran andethoxymethylfurfural using methods known in the art.

Apparatus

Any suitable apparatus may be used in the methods described herein. Themethods may be performed in a continuous or batch apparatus.

With reference to FIG. 1, an exemplary continuous apparatus is depicted.Apparatus 100 has column 108, with feed inlet 102, bottoms outlet 104,and vapor outlet 106. In an exemplary process that may utilize apparatus100, the 5-(halomethyl)furfural (in liquid form) and solvent areprovided to column 108 via feed inlet 102 (either as individual feedstreams or as a combined feed stream). The 5-(halomethyl)furfural andsolvent form a mixture in column 108, and may be heated by externalheating device 110 to a temperature suitable to boil the mixture incolumn 108 to produce gaseous 5-(halomethyl)furfural. It should beunderstood that an internal heating device may also be used in thealternative, or in combination with heating device 110. The gaseous5-(halomethyl)furfural produced exits through vapor outlet 106, leavingbehind the bottoms from the mixture. The bottoms may include, forexample, the solvent and any impurities that may have been present inthe 5-(halomethyl)furfural provided. The bottoms remaining in column 108may be removed via bottoms outlet 104. The 5-(halomethyl)furfural, andoptionally additional solvent, may be continuously added to theapparatus via feed inlet 102, while the gaseous 5-(halomethyl)furfuralis continuously removed via vapor outlet 106.

With reference to FIG. 2, an exemplary batch apparatus is depicted.Apparatus 200 has column 204, with inlet/outlet 202. In an exemplaryprocess that may utilize apparatus 200, the 5-(halomethyl)furfural (inliquid form) and solvent are provided to column 204 via inlet/outlet 202(either as individual feed streams or as a combined feed stream). The5-(halomethyl)furfural and solvent form a mixture in column 204, and maybe heated by external heating device 210 to a temperature suitable toboil the mixture in column 204 to produce gaseous5-(halomethyl)furfural. As discussed above, it should be understood thatan internal heating device may also be used in the alternative, or incombination with heating device 210.

The gaseous 5-(halomethyl)furfural produced exits through inlet/outlet202, leaving behind the bottoms from the mixture.

With reference to FIG. 3, another exemplary apparatus is depicted.Apparatus 300 has still flask 302 connected to receiving flask 306 (alsoknown in the art as the distillate flask). Crude 5-(halomethyl)furfuralis provided to still flask 302, which is heated by heat source 304. Theheat source may, for example, be an oven. When heated, a vapor phasethat includes 5-(halomethyl)furfural is formed, and such vapor phaseenters receiving flask 306, where the vapor phase is cooled by a coolingsource 308 to obtain purified 5-(halomethyl)furfural. The cooling sourcemay, for example, be a cool bath. It should be understood that, asdepicted in FIG. 3, vacuum is connected to receiving flask 306 so thatvolatile materials (e.g., the gaseous 5-(halomethyl)furfural) flow intoreceiving flask 306.

The apparatus described above may include one or more additionalcomponents. For example, the apparatus may have a demister that preventsliquid droplets from leaving the vapor outlet. The apparatus may have aninlet diffuser to increase the surface area of the feed (e.g., theliquid 5-(halomethyl)furfural).

Other apparatuses may be used for the methods described herein. Forexample, in one embodiment, the apparatus may include one or more trays.In another embodiment, the apparatus may be a fractional distillationcolumn. In yet another embodiment, the apparatus may include packaging.In yet another embodiment, the apparatus may be a flash drum, whereinthe feed stream may be saturated with 5-(halomethyl)furfural. In yetanother embodiment, the apparatus may be a wiped film evaporator,wherein the feed stream includes 5-(halomethyl)furfural.

Thus, provided are also systems that include any of the apparatusdescribed above; 5-(halomethyl)furfural; and any of the solventsdescribed herein.

Enumerated Embodiments

The following enumerated embodiments are representative of some aspectsof the invention.

-   1. A method comprising boiling a mixture comprising    5-(halomethyl)furfural and solvent to produce gaseous    5-(halomethyl)furfural, wherein the solvent has a boiling point at    or above the boiling point of the 5-(halomethyl)furfural.-   2. A method comprising contacting a mixture comprising    5-(halomethyl)furfural and solvent with a stripping agent to produce    gaseous 5-(halomethyl)furfural, wherein the stripping agent has a    vapor pressure above the vapor pressure of 5-(halomethyl)furfural.-   3. The method of embodiment 2, wherein the stripping agent is an    inert gas.-   4. The method of embodiment 2, wherein the stripping agent is    hydrogen, nitrogen, argon, helium, or any combinations or mixtures    thereof.-   5. The method of any one of embodiments 1 to 4, wherein the method    is performed at an operating pressure of at least 20 torr.-   6. The method of embodiment 5, wherein the method is performed at an    operating pressure of between 30 torr and 2000 torr.-   7. The method of any one of embodiments 1 to 6, wherein the solvent    comprises one or more aromatic solvents, one or more heavy alkane    solvents, one or more ester solvents, one or more silicone oils, or    any combinations or mixtures thereof.-   8. The method of any one of embodiments 1 to 6, wherein the solvent    comprises one or more alkyl phenyl solvents.-   9. The method of any one of embodiments 1 to 6, wherein the solvent    comprises dodecylbenzene, diphenyl ether, sulfolane, hexadecane,    heptadecane, octadecane, icosane, heneicosane, docosane, tricosane,    tetracosane, naphthalene, anthracene, tetramethylnaphthalene, or any    combinations or mixtures thereof.-   10. The method of any one of embodiments 1 to 9, further comprising    condensing the gaseous 5-(halomethyl)furfural to obtain    5-(halomethyl)furfural in liquid form.-   11. The method of any one of embodiments 1 to 9, further comprising    depositing the gaseous 5-(halomethyl)furfural to obtain    5-(halomethyl)furfural in solid form.-   12. The method of any one of embodiments 1 to 11, wherein the    5-(halomethyl)furfural is 5-(chloromethyl)furfural.-   13. The method of any one of embodiments 1 to 12, wherein the    5-(halomethyl)furfural is provided in a 5-(halomethyl)furfural    composition, and wherein the 5-(halomethyl)furfural composition has    less than 5 wt % of acid.-   14. A system comprising:    -   a purification apparatus;    -   5-(halomethyl)furfural; and    -   solvent, wherein the solvent has a boiling point at or above the        boiling point of the 5-(halomethyl)furfural.-   15. The system of embodiment 14, wherein the solvent comprises one    or more aromatic solvents, one or more heavy alkane solvents, one or    more ester solvents, one or more silicone oils, or any combinations    or mixtures thereof.-   16. The system of embodiment 14, wherein the solvent comprises one    or more alkyl phenyl solvents.-   17. The system of embodiment 14, wherein the solvent comprises    dodecylbenzene, diphenyl ether, sulfolane, hexadecane, heptadecane,    octadecane, icosane, heneicosane, docosane, tricosane, tetracosane,    naphthalene, anthracene, tetramethylnaphthalene, or any combinations    or mixtures thereof.-   18. The system of any one of embodiments 14 to 17, wherein the    purification apparatus comprises:    -   a column;    -   a feed inlet, wherein the feed inlet is connected to the column        and configured to allow a feed stream comprising        5-(halomethyl)furfural to enter into the column;    -   a vapor outlet, wherein the vapor outlet is connected to the        column and configured to allow gaseous 5-(halomethyl)furfural        produced to exit the column;    -   a bottoms outlet, wherein the bottoms outlet is connected to the        column and configured to allow bottoms remaining from the feed        stream to exit the column; and    -   a heat source, wherein the heat source is configured to heat the        column.-   19. The system of any one of embodiments 14 to 17, wherein the    purification apparatus comprises:    -   a column;    -   an inlet/outlet; wherein the inlet/outlet is connected to the        column and configured to allow a feed stream comprising        5-(halomethyl)furfural to enter into the column and to allow        gaseous 5-(halomethyl)furfural produced to exit the column; and        a heat source, wherein the heat source is configured to heat the        column.-   20. The system of any one of embodiments 14 to 17, wherein the    purification apparatus comprises:    -   a still flask, wherein the still flask is configured to receive        a feed stream comprising 5-(halomethyl)furfural;    -   a receiving flask, wherein the receiving flask is configured to        receive gaseous 5-(halomethyl)furfural produced from the feed        stream in the still flask, and wherein the receiving flask is        connected to the still flask;    -   a heat source, wherein the heat source is configured to heat the        still flask; and    -   a cooling source, wherein the cooling source is configured to        cool the receiving flask.

EXAMPLES

The following Examples are merely illustrative and are not meant tolimit any aspects of the present disclosure in any way.

Example 1 Distillation to Purify 5-(Chloromethyl)furfural (CMF) UsingToluene

Crude CMF and toluene were combined and washed with brine (2×100 mL, 20°C.; saturated aqueous solution of sodium chloride) in a separatoryfunnel in order to remove trace amounts of hydrochloric acid and water.The oven on a kugelrohr apparatus was pre-heated to 110° C. The bottomsflask of the kugelrohr apparatus was charged with 86.5 g of the washedsolution containing the crude CMF and toluene were loaded into the oven.In turn, the receiving flask was chilled to 0° C., and the system wasevacuated to about 90 torr. The distillation of toluene was continueduntil no visible material was observed to be distilling from the bottomsflask (about 1 hr). The kugelrohr apparatus was allowed to return toatmospheric pressure. In turn, the receiving flask containing thetoluene was replaced with a clean distillate flask. The system wasevacuated to about 90 torr, the oven temperature was raised to 190° C.,and the distillate flask was chilled to 0° C. Under these conditions,CMF distilled into the distillate bulb (6.01 g collected), indicatingthat there was an undetectable amount of impurities in the CMFcollected. The run time was for 1 hour and 45 min to remove all of theCMF from the bottoms. Distillation yield was not determined, and sampleswere not taken after the brine wash for analysis.

Analytical Methods

CMF was analyzed according to the following protocol. Quantitation ofCMF by HPLC was performed on an Agilent 1100 HPLC with UV detection at280 nm. The column was an Agilent RX-Sil, 4.6×100 mm column with 1.8 umparticle size. The mobile phase was 4:1 hexane/tetrahydrofuran pumped at1 mL/min at a temperature of 50° C. A 1 uL injection was used. Theretention time for CMF was typically observed around 2.7 minutes. CMFwas quantitated by comparison of peak areas to a known standardconcentration of CMF.

Example 2 Distillation to Purify 5-(Chloromethyl)furfural (CMF) UsingLinear Alkyl Benzenes

The oven on a kugelrohr apparatus was pre-heated to 190° C. The bottomsflask was charged with a crude CMF, toluene and a linear alkyl benzene(run #1: Cepsa Petrelab 550-Q; run #2: Cepsa Petrene 900-Q). The amountsof crude CMF, toluene and linear alkyl benzene for each reaction aresummarized in Table 1 below. In turn, the receiving flask was chilled to0° C., and the kugelrohr apparatus was evacuated to about 90 torr. Underthese conditions, CMF distilled into the distillate bulb. Anundetectable amount of impurities in the CMF collected. CMF was analyzedaccording to the following protocol described in Example 1 above.

TABLE 1 Mass of Mass of Mass of Mass of Crude linear alkyl DistillateCMF in CMF and linear alkyl benzene Collected Distillate Run # Toluene(g) benzene (g) (g) (g) 1 115.5 Cepsa Petrelab 157 68 44.9 550-Q 2 127Cepsa Petrene 181 88.5 83.1 900-Q

Example 3 Distillation of Crude 5-(Chloromethyl)furfural (CMF) WithoutSolvent

To the bottom flask of the kugelrohr apparatus was added 6.35 g of crudeCMF (composed of 5.2 g of CMF, 82% pure). The system was evacuated toabout 20 torr and then the receiving flask was chilled to −78° C. TheCMF started to distill at 151° C. The temperature was ramped up slowlyup to 160° C. to distill more CMF. Total duration: 3 hours. Thedistillation yielded 3.23 g of CMF (102% pure), and 0.2 g of CMF wasrecovered in the bottom flask which gives a mass recovery of 66% in CMF.

Distillation yield and mass recovery were calculated as follows:

Distillation yield=(mass of CMF in distillate flask at the end of theprocess/mass of CMF in still flask at the beginning of the process)×100%

Mass recovery of CMF=([mass of CMF in still flask at the end of theprocess+mass of CMF in distillate flask at the end of the process]/massof CMF in still flask at the beginning of the process)×100%

The results are summarized as follows:

Initial CMF purity: 82%

Final CMF purity: 102%

Distillation yield: 62%

Mass recovery of CMF: 66%

Example 4 Distillation of Crude 5-(Chloromethyl)furfural (CMF) inWibaryl® A

To the still flask of the kugelrohr apparatus was added 39 g of crudeCMF (composed of 19.4 g of CMF (49%) and 17.3 g of toluene (39%)), 3.9 gof NaCl and 40.5 g of Wibaryl® A. To remove toluene, 500 ml of organiceffluent (5.2 g of CMF, 1% loading) was concentrated under vacuum togive the crude oil CMF used for the distillation.

The CMF loading for the distillation in Wibaryl® A was 25%. The systemwas evacuated to about 1 torr and then the distillate flask was chilledto −78° C. At first the toluene was distilled at 35-40° C. over 1.5 h.The vacuum and heating was stopped and the toluene was removed. Then thesystem was again evacuated to about 1 torr and then the new distillateflask was chilled again to −78° C. The CMF started to distill at 80° C.The temperature was ramped up slowly up to 110° C. to distill more CMF.Total duration: 4.5 hours

Distillation yield and mass recovery were calculated as set forth inExample 3 above. The results are summarized as follows:

Initial CMF purity: 49%

Final CMF purity: 96.5%

Distillation yield: 80%

Mass recovery of CMF: 81%

Example 5 Argon Stripping of Crude 5-(Chloromethyl)furfural (CMF) inWibaryl® A

To a two-neck-round-bottom flask (still flask) were added 82.5 g ofcrude CMF (58.1 g of CMF, 70.5% pure) and 253.5 g of Wibaryl° A (3:1ratio with crude CMF). One of the necks of the flask was then connectedthrough a distillation adapter to another two-neck-round-bottom flask(distillate flask). The other neck was equipped with a gas dispersionapparatus to ensure homogeneous flow of argon through the solutionmixture. The distillate flask was chilled to −90° C. (Liquid N₂/Hexanemixture). The remaining neck of the distillate flask was connectedthrough a hose to a cold finger trap cooled at −90° C. (Liquid N₂/Hexanemixture). Argon was vigorously bubbled (2 psi) in the flask containingthe crude CMF and this solution was also heated gradually from 60° C. to190° C. for 9 hours to promote more CMF to be stripped and isolated inthe distillate flask. The CMF started to distill slowly around 90° C.but more material was trapped around 165° C. The stripping experimentyielded 6.5 g of CMF (97.6% pure) and 6.15 g of CMF was recovered in thestill flask which gives a mass recovery of 22%.

The stripping yield and mass recovery were calculated as follows:

Stripping yield=(mass of CMF in distillate flask at the end of theprocess/mass of CMF in still flask at the beginning of the process)×100%

Mass recovery of CMF=([mass of CMF in still flask at the end of theprocess+mass of CMF in distillate flask at the end of the process]/g CMFin still flask at the beginning of the process)×100%

The results are summarized as follows:

Initial CMF purity: 70.5%

Final CMF purity: 97.6%

Stripping yield: 11.2%

Mass recovery of CMF: 22%

1. (canceled)
 2. A method for purifying 5-(halomethyl)furfural,comprising: a) providing a 5-(halomethyl)furfural composition to apurification apparatus, wherein the 5-(halomethyl)furfural compositioncomprises 5-(halomethyl)furfural and one or more impurities, and whereinthe 5-(halomethyl)furfural composition has a mass ratio of the one ormore impurities to the 5-(halomethyl)furfural; b) providing a strippingagent to the purification apparatus, wherein the stripping agent has avapor pressure above the vapor pressure of 5-(halomethyl)furfural; andc) vaporizing the 5-(halomethyl)furfural in the 5-(halomethyl)furfuralcomposition by contacting the stripping agent with the5-(halomethyl)furfural composition to form gaseous5-(halomethyl)furfural, wherein the gaseous 5-(halomethyl)furfural has amass ratio of the one or more impurities to the 5-(halomethyl)furfuralthat is lower than the mass ratio for the 5-(halomethyl)furfuralcomposition.
 3. The method of claim 2, further comprising condensing thegaseous 5-(halomethyl)furfural to obtain purified 5-(halomethyl)furfuralin liquid form.
 4. The method of claim 2, further comprising depositingthe gaseous 5-(halomethyl)furfural to obtain 5-(halomethyl)furfural insolid form.
 5. The method of claim 2, further comprising boiling the5-(halomethyl)furfural composition in the purification apparatus toobtain a second gaseous 5-(halomethyl)furfural, wherein the secondgaseous 5-(halomethyl)furfural has a mass ratio of the one or moreimpurities to the 5-(halomethyl)furfural that is lower than the massratio for the 5-(halomethyl)furfural composition.
 6. The method of claim2, wherein the 5-(halomethyl)furfural is 5-(chloromethyl)furfural.
 7. Amethod for purifying 5-(halomethyl)furfural, comprising: a) providing a5-(halomethyl)furfural composition to a purification apparatus, whereinthe 5-(halomethyl)furfural composition comprises 5-(halomethyl)furfuraland one or more impurities, and wherein the purification apparatus hasan operating temperature of at least 140° C. and an operating pressureof at least 30 torr; and b) boiling the 5-(halomethyl)furfuralcomposition to obtain gaseous 5-(halomethyl)furfural, wherein thegaseous 5-(halomethyl)furfural has a mass ratio of the one or moreimpurities to the 5-(halomethyl)furfural that is lower than the massratio for the 5-(halomethyl)furfural composition.
 8. The method of claim7, wherein the operating pressure is between 30 torr and 2000 torr. 9.The method of claim 7, wherein the 5-(halomethyl)furfural provided tothe purification apparatus has less than 30 wt % of the one or moreimpurities.
 10. The method of claim 7, wherein the5-(halomethyl)furfural provided to the purification apparatus has lessthan 5 wt % of residual hydrochloric acid.
 11. The method of claim 7,further comprising condensing the gaseous 5-(halomethyl)furfural toobtain purified 5-(halomethyl)furfural in liquid form.
 12. The method ofclaim 7, further comprising depositing the gaseous5-(halomethyl)furfural to obtain purified 5-(halomethyl)furfural insolid form.
 13. The method of claim 7, wherein the5-(halomethyl)furfural is 5-(chloromethyl)furfural.